In some situations, various vehicles undergo testing as part of the overall development and/or certification process. For example, some aircraft may undergo a Low Level Pulse or Low Level Continuous Wave (LLP/LLCW) test during initial first article inspection and/or during routine maintenance and inspections. Under the LLP or LLCW test, a low level electrical current (generally fewer than 10 amps) is transmitted through various elements of the vehicle to evaluate current flow behavior through the vehicle. Changes in current flow behavior as exhibited during such tests are important indicators of the manner in which current may flow through such a vehicle during a lightning strike. Lightning strikes may affect structural elements, performance, and/or operation of installed electrical/electronic equipment and wiring. The LLP or LLCW tests may be used to verify the performance of a number of electromagnetic protection features. Examples of vehicles that may undergo LLP or LLCW testing include aircraft vehicles, maritime vessels, automobiles, and other large investment assemblies.
Although the LLP or LLCW tests may be extrapolated to understand the impacts of an actual high intensity electrical current pulse such as a lightning strike, further testing and/or maintenance may be required in the event of the vehicle receiving an actual lightning strike. For example, if lightning were to strike a composite based structure, the current is likely to flow from the higher impedance composite structures through lower impedance conductive metal structures (e.g., through metallic fasteners). In such an event, the fasteners that act as intermediary electrical connections between the composite and metal elements may be in need of inspection. Since it may be difficult to see visual evidence of the magnitude of such transient current flows, systems and methods are needed to understand the effects on electrical currents on structures and fasteners.